Battery

Abstract

A flat electrode body of a battery has a first-side curved end positioned on a first side of an electrode body width direction and a second-side curved end positioned on a second side. A positive electrode innermost curved portion of a positive electrode sheet is disposed inside the first-side curved end. When the dimension from a positive electrode connecting portion to the end on the first side of the electrode body is defined as a distance and the dimension from the positive electrode connecting portion to the end on the second side of the electrode body is defined as a distance, the positive electrode connecting portion being in the positive electrode protrusion wound portion and connected to a terminal connecting portion of a positive terminal member, the terminal connecting portion is connected to the positive electrode connecting portion at a position satisfying the condition Ha≥1.1Hb.

The invention claimed is: 
     
       1. A battery comprising:
 an electrode body including a strip-shaped positive electrode sheet and a strip-shaped negative electrode sheet having higher heat conductivity than the positive electrode sheet, the positive electrode sheet and the negative electrode sheet being overlapped and wound about an axis in a flat shape by interposing strip-shaped separators made of porous resin between the positive and negative electrode sheets, the electrode body having a positive-electrode protruding wound part that is formed of an edge portion of the positive electrode sheet on one side in a width direction and protrudes in a flat spiral form toward a first side in an axial direction; and 
 a positive terminal member having a terminal connecting portion connected to the positive-electrode protruding wound part of the electrode body, 
 wherein the electrode body being flat, includes: 
 a first-side curved end part located on a first side in an electrode body width direction intersecting the axial direction and an electrode body thickness direction, and formed of the positive electrode sheet, the negative electrode sheet, and the separators which are bent in a semi-cylindrical shape and overlapped one on another; and 
 a second-side curved end part located on a second side in the electrode body width direction and formed of the positive electrode sheet, the negative electrode sheet, and the separators which are bent in a semi-cylindrical shape and overlapped one on another, 
 wherein the positive electrode sheet includes a positive-electrode innermost curved portion bent at smallest radius curvature and placed in the first-side curved end part, 
 when a dimension in the electrode body width direction from a positive-electrode connecting portion of the positive-electrode protruding wound part connected to the terminal connecting portion to an end of the first-side curved end part of the electrode body on the first side in the electrode body width direction is defined as a distance Ha, and a dimension in the electrode body width direction from the positive-electrode connecting portion to an end of the second-side curved end part of the electrode body in the electrode body width direction is defined as a distance Hb, 
 the terminal connecting portion is connected to the positive-electrode connecting portion at a position where the distance Ha and the distance Hb satisfy a relation 2.51Hb≥Ha≥1.1Hb. 
 
     
     
       2. The battery according to  claim 1 , further comprising a battery case accommodating the electrode body and having a terminal fixing wall part to which the positive terminal member is fixed and extended through to outside,
 wherein the electrode body is accommodated in the battery case in a configuration that the electrode body width direction intersects the terminal fixing wall part and the second-side curved end part is located on a side closer to the terminal fixing wall part than the first-side curved end part. 
 
     
     
       3. The battery according to  claim 1 , wherein
 when a dimension of a central part of the electrode body in the electrode body width direction, the central part being located between the first-side curved end part and the second-side curved end part, is defined as a dimension He, and 
 a dimension of the positive-electrode connecting portion in the electrode body width direction is defined as a dimension Hc, 
 the dimension He is a value meeting a relation of Hc≤0.5He. 
 
     
     
       4. The battery according to  claim 1 , wherein
 when a thickness of the electrode body is a thickness Wa, 
 the distance Ha and the distance Hb satisfy a relation of Ha≥Wa and Hb≥Wa. 
 
     
     
       5. The battery according to  claim 1 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       6. The battery according to  claim 5 , wherein
 when a dimension of a central part of the electrode body in the electrode body width direction, the central part being located between the first-side curved end part and the second-side curved end part, is defined as a dimension He, and 
 a dimension of the positive-electrode connecting portion in the electrode body width direction is defined as a dimension Hc, 
 the dimension He is a value meeting a relation of Hc≤0.5He. 
 
     
     
       7. The battery according to  claim 3 , wherein
 when a thickness of the electrode body is a thickness Wa, 
 the distance Ha and the distance Hb satisfy a relation of Ha≥Wa and Hb≥Wa. 
 
     
     
       8. The battery according to  claim 5 , wherein
 when a thickness of the electrode body is a thickness Wa, 
 the distance Ha and the distance Hb satisfy a relation of Ha≥Wa and Hb≥Wa. 
 
     
     
       9. The battery according to  claim 6 , wherein
 when a thickness of the electrode body is a thickness Wa, 
 the distance Ha and the distance Hb satisfy a relation of Ha≥Wa and Hb≥Wa. 
 
     
     
       10. The battery according to  claim 2 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       11. The battery according to  claim 1 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       12. The battery according to  claim 3 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       13. The battery according to  claim 4 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       14. The battery according to  claim 5 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       15. The battery according to  claim 6 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       16. The battery according to  claim 7 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion. 
 
     
     
       17. The battery according to  claim 8 , wherein the positive-electrode connecting portion of the positive-electrode protruding wound part consists of all of overlapping portions of the edge portion forming the positive-electrode protruding wound part having a flat spiral form, the overlapping portions overlapping the terminal connecting portion of the positive terminal member when seen in the electrode body thickness direction, and
 the overlapping portions are all bound together in a bundle and welded to the terminal connecting portion.